Rhizobium tropici-derived extracellular polymeric substances (EPS) have been used in soils to enhance soil structures and mitigate soil erosions. However, information on their use to improve soil health and fertility ...Rhizobium tropici-derived extracellular polymeric substances (EPS) have been used in soils to enhance soil structures and mitigate soil erosions. However, information on their use to improve soil health and fertility indicators, and plant growth is limited. In a greenhouse study, we investigated their effects on some soil health, soil fertility indices, and the growth of black-eyed peas (Vigna unguiculate). Results showed that soils incubated with EPS significantly increased basal soil respiration, soil microbial biomass, permanganate oxidizable carbon (POC), and potentially mineralizable nitrogen (PMN). The EPS shifted microbial populations from bacteria to fungi and Gram (−ve) to Gram ( ve) bacteria. However, it had little or no effects on soil pH, soil organic matter (SOM), and cation exchange capacity (CEC). The EPS decreased soil moisture loss, increased soil aggregate stability, but delayed blacked-eyed peas germinations in the soils. At 0.1% (w/w) concentrations in soils, there was increase in plant root nodulations and vegetative growth. This study was carried out within 40 days of incubating soils with EPS or growing the black-eyed peas in a greenhouse study. The plant growth parameters were taken before flowering and fruiting. Further studies of the effects of incubating soils with the extracellular polymeric substances on plant growth. Soil microbial biomass, microbial diversities, and other soil fertility indices are deemed necessary.展开更多
An efficient fibrous catalyst for the biodiesel fuel production has been synthesized by radiation-induced graft polymerization of 4-chloromethylstyrene onto a nonwoven polyethylene (NWPE) fabric followed by amination ...An efficient fibrous catalyst for the biodiesel fuel production has been synthesized by radiation-induced graft polymerization of 4-chloromethylstyrene onto a nonwoven polyethylene (NWPE) fabric followed by amination with trimethylamine (TMA) and further treatment with NaOH. The degree of grafting of NWPE fabric and TMA group density of fibrous catalyst could easily and reproducibly be controlled within a range of up to 340% and 3.6 mmol-TMA/g-catalyst, respectively. In the transesterification of triglycerides and ethanol using the synthesized fibrous catalyst, the conversion ratio of triglycerides reached 95% after 4 h reaction at 50°C.展开更多
研究了一种以生物质裂解油为原料制备氢气和生物燃料的催化转化过程。该过程包括生物油催化裂解制备氢气和生物合成气，合成气的调变，烯烃聚合和费脱合成耦合制备生物燃料。在优化反应条件下，氢气产率达到120.9 g H2/（kg bio-oil）...研究了一种以生物质裂解油为原料制备氢气和生物燃料的催化转化过程。该过程包括生物油催化裂解制备氢气和生物合成气，合成气的调变，烯烃聚合和费脱合成耦合制备生物燃料。在优化反应条件下，氢气产率达到120.9 g H2/（kg bio-oil），烯烃聚合-费脱合成耦合反应形成的生物燃料产率达到526.1 g/（kg bio-syngas）。基于产物分析和催化剂特性表征，探讨了生物燃料合成过程中的反应路径和化学反应过程.展开更多
文摘Rhizobium tropici-derived extracellular polymeric substances (EPS) have been used in soils to enhance soil structures and mitigate soil erosions. However, information on their use to improve soil health and fertility indicators, and plant growth is limited. In a greenhouse study, we investigated their effects on some soil health, soil fertility indices, and the growth of black-eyed peas (Vigna unguiculate). Results showed that soils incubated with EPS significantly increased basal soil respiration, soil microbial biomass, permanganate oxidizable carbon (POC), and potentially mineralizable nitrogen (PMN). The EPS shifted microbial populations from bacteria to fungi and Gram (−ve) to Gram ( ve) bacteria. However, it had little or no effects on soil pH, soil organic matter (SOM), and cation exchange capacity (CEC). The EPS decreased soil moisture loss, increased soil aggregate stability, but delayed blacked-eyed peas germinations in the soils. At 0.1% (w/w) concentrations in soils, there was increase in plant root nodulations and vegetative growth. This study was carried out within 40 days of incubating soils with EPS or growing the black-eyed peas in a greenhouse study. The plant growth parameters were taken before flowering and fruiting. Further studies of the effects of incubating soils with the extracellular polymeric substances on plant growth. Soil microbial biomass, microbial diversities, and other soil fertility indices are deemed necessary.
文摘An efficient fibrous catalyst for the biodiesel fuel production has been synthesized by radiation-induced graft polymerization of 4-chloromethylstyrene onto a nonwoven polyethylene (NWPE) fabric followed by amination with trimethylamine (TMA) and further treatment with NaOH. The degree of grafting of NWPE fabric and TMA group density of fibrous catalyst could easily and reproducibly be controlled within a range of up to 340% and 3.6 mmol-TMA/g-catalyst, respectively. In the transesterification of triglycerides and ethanol using the synthesized fibrous catalyst, the conversion ratio of triglycerides reached 95% after 4 h reaction at 50°C.
文摘温敏材料是重要的智能材料之一。虽然温敏均聚物具有良好的环境敏感性能,但其力学性能无法满足使用要求,且部分温敏均聚物的最低临界溶解温度(Lower critical solution temperature,LCST)难以改变,从而限制了其应用领域。当温敏聚合物与其他基材复合或接枝共聚时,可以有效提升温敏材料的力学性能,同时通过改变物料组成及配比可以调节温敏材料的临界温度,拓展其应用范围。制备温敏智能材料的原料大多来源于不可再生的石油资源,随着石油资源日渐匮乏,人们逐渐将目光转移到其他资源。生物质作为可再生资源,广泛存在于自然界中,具有资源丰富、可持续利用的优点,特别是其含有羟基、胺基、醚键和羧基等活性官能团,可以提供多种活性位点,与温敏单体接枝共聚来制备温敏材料,是一种很好的温敏材料基材。已成功应用在生物质温敏智能材料中的生物质原料包括纤维素、纤维素醚、半纤维素、木质素、壳聚糖等。然而,制备生物质基温敏智能材料的接枝共聚方法单一,传统的自由基共聚制备的温敏材料存在温度响应范围窄、产生温敏均聚物较多且难分离以及制备的材料形态单一等问题。生物质温敏材料的接枝共聚方法已经从最初的以引发剂引发的普通自由基聚合发展到可控性较强的光引发自由基聚合、原子转移自由基聚合(Atom transfer radical polymerization,ATRP)、单电子转移活性自由基聚合(Single election transfer living radical polymerization,SET-LRP)、可逆加成-断裂链转移法(Reversible addition-fragmentation chain transfer,RAFT)等接枝共聚方法。温敏接枝单体较多,其中研究最多的为N-异丙基丙烯酰胺(N-isopropylacrylamide,NIPAM),其具有明确的临界溶解温度,且最低临界溶解温度与人体温度相差不大,它与生物质材料一起制备的温敏性膜、温敏性水凝胶和温敏性微球等在药物释放、组织工程和工农业等方面具有广泛的应用。本文详细归纳了生物质大分子制备温敏材料的方法,对这些接枝共聚方法的特点进行总结,同时介绍了制备温敏材料涉及的温敏物质、温度响应机理以及生物质基温敏智能材料的应用,最后总结了现阶段生物质基温敏智能材料制备及应用中存在的难点,并对未来的技术发展进行了展望。
